Well casing hanger and method for hanging same



Oct. 18, 1966 c. c. BROWN ETAL 3,279,539

WELL CASING HANGER AND METHOD FOR HANGING SAME c. E. WAKEFIELD IR.

Oct. 18, 1966 c. c. BROWN ETAL 3,279,539

WELL CASING HANGER AND METHOD FOR HANGING SAME Filed Feb. 12, 1965 5 Sheets-Sheet 2 INVENTORS.

Oct. 18, 1966 c. c. BROWN ETAL 3,279,539

WELL CASING HANGER AND METHOD FOR HANGING SAME Filed Feb. 12, 1965 3 Sheets-Sheet 5 'ENTORS. /04 6 C A/ 45 M?!" an, J6.

United States Patent ware Filed Feb. 12, 1965, Ser. No. 432,160 27 Claims. (Cl. 166-27) This is a continuation-in-part of application Serial No. 310,333 filed September 20, 1963 (now abandoned).

The present inveniton relates to the production of oil and gas from a well, and more particularly, relates to apparatus and a method for hanging a casing in a casing head whereby the casing is positively locked in the casing head prior to cementing the casing in the formation.

In the prior art, the well casing is run into the well, landed in the casing head, and cemented into the formation with excess cement returns passing out the well between the casing and the casing head. A packer or other sealing means is then run on the casing string to seal between the casing and the casing head, thus requiring an additional trip into the hole to position the packer. It is also the practice in the prior art to land the casing and pack off between the casing and the casing head prior to cementing, since the pack ofl? means were also the means for locking the casing into the casing head, after which the casing was cemented into the formation. Such practices have the inherent disadvantage of requiring the provision of additional means for returning the cement to the surface, such as an outlet or a port collar below the casing hanger.

According to another prior art practice, well casing is run into a well through a casing head having a packing element therein so that a shoulder on the upper portion of the casing lands within the casing head on the packing element to extrude the packer by the weight of the casing. It has been found, however, that the shoulder on the casing dose not always properly seat against the packing element in the casing head, and in such cases does not properly seal off between the casing head and the casing. The malfunctioning of this sealing arrangement cannot be detected until after the casing has been cemented into the formation, at which time the repairs are relatively expensive,

It is, therefore, an object of our present invention to provide a casing hanger which is landed in a casing head and has positive means of extruding packing elements between the casing and the casing head.

It is also an object of our present invention to provide a casing hanger whereby the casing may be hung in the casing head and cemented into the formation prior to packing off the casing within the casing head without requiring an additional trip into the hole to position packing means.

It is another object of our present inveniton to provide a means for packing off a casing within a casing head after the casing is cemented into the formation without making a trip into the hole to position packing means.

It is a further object of the present invention to provide a mechanical means for remotely setting a casing hanger seal in a casing nest wherein said casing is mechanically locked.

It is a further object of this invention to provide a hydraulic means of setting a casing hanger seal that obviates the necessity of rotation or manipulation of the setting string and requires only the exertion of pump pressure through the setting string to set the casing hanger seal.

A further object of the present invention is to provide 3,279,539 Patented Oct. 18, 1966 a casing hanger assembly having hydraulically actuated locking means to hold the sealing element seat after setting pressure has been released.

Another object of the present invention is to provide a casing hanger assembly having pressure equalizing means to prevent premature setting of the seal between the casing and the casing head by pressure differentials to which the casing hanger assembly may be subjected during the cementing operation.

Other objects and a more complete understanding of our present invention may be had by reference to the following specification taken in conjunction with the appended claims and the drawings, wherein:

FIG. 1 shows the casing hung according to the present invention within the casing head showing the casing head and tubing head mounted in a well;

FIG. 2 shows in partial cross section the casing hanger locking and sealing apparatus;

FIG. 3 shows in partial cross section the casing hanger running and setting tool used in conjunction with the present invention;

FIG. 4 is a view, partly in section and partly in elevation, of a form of the present invention modified for hydraulic setting of the casing hanger seal, showing the casing hanger as it is carried in the hole by the running and setting tool and landed against the indexing shoulder in the casing head;

FIG. 5 is a view, partly in section and partly in elevation, showing the relation of the apparatus of FIG. 4 at the point directly after the cementing operation is carried out showing the plugs in place in the landing collar.

FIG. '6 is a view, partly in section and partly in elevation showing the relation of the apparatus of FIGS. 4 and 5 after the setting ball is dropped through the setting string and pressure is applied to set the packer;

FIG. 7 is a view, partly in section and partly in elevation, showing the relation of the apparatus of FIGS. 4-6 as the setting tool is released from the casing hanger and is being removed from the hole.

Referring now to the drawings generally, our present invention involves a means for hanging the casing 60 within a casing head 61 by locking the casing down on a shoulder 79 within the casing head with a spring loaded dog 80, after which the casing can be cemented into the formation prior to setting the packer 94 so that the cement returns may be circulated through the annulus 81. The expression casing head as used herein refers to any well member in which a casing is landed or hung, including a casing hanger mandrel where multiple casings are hung one within another. The packing element 94 is then extruded to seal off the annulus 81 without making an additional trip into the hole, that is without retrieving the running tool and then running a setting tool to position packing or sealing means.

Referring now more particularly to FIGS. 1 and 2 of the drawings, a casing hanger mandrel 62 is installed on the upper end of the casing string 60 equipped with a conventional shoe and collar (not shown) on and near the bottom thereof. The casing hanger running and setting tool 63, shown in FIG. 3, is then inserted in the easing hanger mandrel 62 with the lugs 64 of the setting nut 66 entering the splines 68 of the casing hanger drive sleeve 92 and the running and setting tool lowered into the casing hanger mandrel '62 on a drill pipe (not shown) until the bearing race 72 rests on top 74 of the mandrel of the casing hanger mandrel 62. The floating nut 76 of the running and setting tool, which nut is connected thereto by interengaging longitudinal splines, is threaded into the casing hanger at 78 by rotating the drill pipe to the left. Although turning the running and setting tool 63 to the left moves the setting nut upwardly, the longitudinal spacing of nut 66 and the number of turns required to move nut 66 up to the position shown are such that the floating nut 76 engages the casing hanger at 78 before the setting nut 66 reaches the shoulder as shown in FIG. 3.

Tool 63 is a running tool for the casing string and because of one advantage of applicants invention, this tool may also serve as a setting tool since an additional trip into the casing head with a setting tool to set packing means may be obviated. Thus, it has been found advantageous to design therunning tool 63 to perform the setting function, although the casing hanger may also be run and the packing means set with a separate tool.

The casing hanger with a casing string attached thereto and running and setting tool inserted therein, is lowered into the well through the blowout preventers (not shown) on the drill string until the dogs 80 are below the shoulder 82 of the casing head 61, as shown in FIG. 2. The casing hanger 62 is then locked down into the casing head 61 since the spring loaded dogs 80 prevent the casing hanger mandrel 62 from moving upward past the shoulder 82 of the casing head. Thus, the casing is positively locked down prior to cementing before packing oif the annular opening 81 between the casing hanger mandrel 62 and the casing head 61 with the packing rubber 94, so that cement returns may pass through the annular opening 81 and circumferentially spaced slots 83 without provision for an additional outlet or port collar below the casing hanger to provide for the expulsion of cement returns from the casing annulus. The shoulder of the casing hanger mandrel which seats on internal shoulder 79 of the casing head, may be any type of interrupted shoulder.

The casing string is then cemented in the formation by pumping cement through the drill string (not shown) and through the running and setting tool 63 in the conventional manner. Pump down plug 84 may thenbe run through the drill pipe with mud and into the position shown in the bottom of the setting tool of FIG. 3 so that the plug 84 engages the liner wiper plug 86, as shown in FIG. 3. thus releasing the liner wiper plug 86 having the pump down plug 84 lodged therein so that the plugs move down the casing to engage the landing collar (not shown)with which they act as a back pressure valve, and effectively pack off the casing after the cement is in place. The purpose of the pump down plug is to separate the cement from the mud with which the cement is chased.

After the casing 60 is cemented into the formation, the packing element 94 is extruded between'the casing hanger mandrel 62 and the casing head 61 by first disengaging the fioating nut 76 from the casing hanger mandrel 62 by rotating the drill pipe (to which the running and setting tool 63 is threadably engaged) to the right. Further rotation of the drill pipe (running and setting tool 63) to the right after the floating nut 76 is released from the casing hanger, drives the setting nut 66 which engages splines 68 downwardly toward the lower shoulder 75 of the top sub. After the setting nut 66 is moved downwardly against shoulder 75, it starts rotating with the running and setting tool so that it shears pins 93 and rotates the drive sleeve '90, screwing it downwardly on the threaded portion 77 of casing hanger mandrel 62 until the packing rubber 94 is extruded between the casing hanger mandrel 62 and the casing head 61. Drive sleeve 90 and the top of the casing hanger mandrel have mating right hand translatory acme threads that cause the drive sleeve to move downwardly against the packing to extrude it when the drive sleeve is rotated to the right. The term extrude as used herein means that the packer or sealing element, e.g. packer 94, is mechanically compressed to form a fluid-tight seal between two members, e.g. casing head 61 and easing hanger mandrel 62. After extruding packer 94, the casing is hung and sealed in the casing head 61 and the casing hanger running and setting tool 63 may be withdrawn from the casing hanger on the An increase in mud pressure shears pin 88,

drill pipe. An addition-a1 casing may be hung in an identical manner within the casing hanger mandrel 62..

A tubing head, as, for example, that shown in FIG. 1, may then be latched or fastened to the casing head and a tubing hung therein through the casing hanger mandrel 62 in any conventional manner,-such as that set forth in our copending application, Serial No. 310,203 filed September 20, 1963 for Tubing Head Apparatus and Method.

The casing hanger assembly shown in FIGS. 1-3 and described above requires rotation to set the packer which packs off between the casing hanger and the casing head in which it is landed. When a casing is being hung on the floor of a body of water from a barge, the barge may become misaligned with the well bore and it is sometimes difficult to rotate the setting tool string from the.

floor of the barge since the setting string isforced hard against the riserpipe causing friction. The modification shown in FIGS. 4-7 is particularly useful in applications Where the above-mentioned difficulty may be present.

FIGS. 4-7 show generally a hydraulic setting means for the-packing element of a casing hanger which is set after the casing hanger has been locked in place in the casing head and after the casing has been cemented into the formation so that cement returns may be circulated through the annulus, as mentioned in conjunction with the description of FIGS. l-3. The apparatus of FIGS. 4-7 also involves a hydraulically actuated locking means that holds the packing element set after setting pressure is released and a novel pressure equalizing means that prevents premature set of the packing element by pressure differentials involved in the cementing operation.

Referring now more particularly to FIG. 4 of the drawings, a casing head C is installed on the upper end of the casing string C which has been cemented into the formation. Casing string C is run into the casing head C1 and cemented into the formation below casing string C and the annulus between casing string C and C. Casing string C is carried in the hole on the running string D which is made up into the running and setting tool S which is attached to the casing hanger mandrelH. FIG. 4 shows the casing hanger mandrel H in position in the casing hanger head just prior to beginning circulation and before the cementing operation- The casing head C is a cylindrical member which may be provided at its lower end with a suitable thread or other suitable fastening means, for attaching to the casing C. Provided within the casing hanger head is an upward facing shoulder suitable for landing and indexing within this member, the casing hanger mandrel H. Provided below shoulder 110 is a downward facing shoulder 111 suitable for locking a hold downmeans 109 of the casing hanger mandrel which will hereinafter be described. The upper part of'the casing head is provided with a conventional means (not shown) for attaching riser pipe.

The casing hanger mandrel H construction includes a cylindrical body 112 provided at its lower end with a thread 113 for attaching casing C Just above this thread is provided a hold down means as described above in conjunction with FIG. 2. Hold down or locking means.

with grooves 115 to allow circulation pastithe shoulder.

when landed in the head. Provided above shoulder 114 is packing 116. At each end of the packing are extrusion dogs 117. Header member 118 abuts the upper part of the packing 116 and is provided with a reduced diameter. and shoulder to receive a setting sleeve 119. V

The setting sleeve 119 is packed 01f by 0 rings 108 provided in an annular ring member 120 disposed between sleeve 119 and body member 112. This annular ring is secured to the mandrel ,H by a snap ring 121 which holds.

the ring against a shoulder provided on the body 112. Provided at 122 is another annular ring packing off the sleeve member 119 and the body 112. This ring is prevented from moving upwardly on the body 112 by snap ring 123. At the upper end of body 112 is a thread 117 or other means suitable for attaching annular ring member 124. A beveled shoulder 134 is provided across the upper end of the body and annular ring member 124 in order to provide a stop for the running and setting tool. This annular ring 124 also packs off the body with sleeve member 119.

The annular rings, 122 and 124, body 112 and sleeve 119 form two chambers, upper chamber 125 and the lower or pressure equalizing chamber 126. Orifices 127 and 128 provided in the body 112 provide fluid communication between chambers 125 and 126 with the interior of the casing hanger mandrel H. Abutting the lower end of annular ring 122 are segmented hold down slip members 129. These segmented slip members are tapered and rest against a mating slip bowl 130 provided in sleeve member 119.

The running and setting tool S is made up in the casing hanger mandrel H by means of a left hand acme thread 131 in the interior of the casing hanger mandrel and a traveling nut member 132 that slides on the running and setting tool body 105 upon splined lugs 133. When the running and setting tool S is fully made up, shoulder 135 of the running and setting tool stops against shoulder 134 of the casing hanger. The upper end of the running and setting tool body is threaded at 106 for connection to the running and setting tool top connector 136. The upper end of the top connector 136 has a box thread 105 for connection to the running string. On the lower face of the top connector is provided a race groove 137. Ball bearings 138 are provided between race groove 137 and the race groove 139 cut in the upper face of bearing member 140. Bearing member 140 surrounds the running and setting tool body and is retained there by a shoulder on the running and setting tool body at 141. Surrounding the running and setting tool body below the bearing member 140 is seal member 142. This seal member is provided with 0 rings to pack off the ports 127 and 128 in the casing hanger mandrel and also ports 143 and 144 in the running and setting tool body 105 when the running and setting tool is made up in the casing hanger mandrel. The seal member mounts on the running and setting tool body in limited longitudinal relationship thereto between shoulder 145 on the bearing member and the upper faces of spline members 133.

A swivel connection 146 is provided at the lower end of the running and setting tool body and the swivel connection carries a shear out collar 147 in order to mount a liner wiper plug 148 thereto. This liner wiper plug is of the conventional type commonly used in oil fields for cementing purposes. Mounted on the lower end of casing C is a conventional landing collar 149. A shoe 104 is provided below the landing collar.

In the use of the apparatus shown in FIGS. 4-7, the apparatus is run into the hole as in FIG. 1 until the shoulder 114 of the casting hanger lands against shoulder 110 of the casing head C At this time the spring loaded hold down dogs 109 will latch against shoulder 111 of the casing hanger head preventing a withdrawal of the hanger from the hole. Circulation may now be established to Wash the well bore preparatory to cementing. After cementing pump down plug 150 is dropped and continued pumping pressure is applied behind the plug to force the cement to position. When plug 150 reaches the linear wiper plug 148 it will latch thereto in sealing relationship. Shoulder 170 prevents further downward movement of plug 150 and slips 172 prevent upward movement of plug 150. A rise in pressure will be noted at the surface until pins 151 are sheared and the liner wiper plug 148 pumped to the landing collar 149 where it will latch with snap rings 103 against being later forced up the hole. When cement is in position and the cementing job completed the casing hanger assembly will appear as in FIG. 5.

During the cementing operation the hydraulic setting means of the casing hanger packer was not set prematurely by differentials pumping pressures since the pressure balancing chambers and 126 are both in communication with the pumping differentials prior to sealing olf the bore of the running and setting tool as hereinafter described.

When the cementing operation is completed, the packer 116 is set by dropping a ball 102 into the running pipe. The ball settles to its seal 152 provided in the running and setting tool body. Pressure is now applied through the running pipe, to pressurize chamber 125 of the casing hanger through ports 143 of the running and setting tool body, 153 of seal member 140, and 127 of the casing hanger mandrel. Pressure build up in chamber 125 forces the annular seal ring member 122 against slip segments 129. The slip segments force the setting sleeve downward also forcing the header member 118 to set seal 116. The assembly will now be in the position as shown in FIG. 6. After the pressures is released the seal is maintained set by the slip bowl in the sleeve being forced into the slip segments causing them to bite into the casing hanger mandrel in holding relationship.

To remove the running and setting tool, the running pipe is rotated to the right causing the running and setting tool to rotate with it. By this rotation the traveling nut 132 is released from the casing hanger mandrel. The running and setting tool may then be lifted up out of engagement with the casing hanger mandrel as shown in FIG. 7. Seal member 142 moves longitudinally allowing the fluid above the ball to drain as the running pipe is pulled from the hole.

Although our present invention has been described with a certain degree of particularity, the scope of the invention is not limited to the details set forth, but is of the full breadth of the appended claims.

We claim:

1. A casing hanger assembly for use with a casing head having a shoulder therein, comprising in combination:

(a) a casing hanger mandrel adapted to land on said shoulder of said casing head,

(b) means defining an annular path between said mandrel and .said casing head, through which path fluids can pass when said mandrel is landed on said casing head shoulder, and

( 0) means associated with said mandrel for eifecting a seal between said mandrel and said casing head, said seal means being so arranged and constructed as to extend said annular path past said seal means before said seal is effected.

2. The apparatus of claim 1 including means associated with said mandrel for locking said mandrel against upward movement relative to said casting head when said mandrel is landed on said shoulder of said casing head.

3. The apparatus of claim 2 wherein said locking means are spring loaded and automatically lock said mandred relative to said casing head when said mandrel is lowered below a predetermined point in said casting head.

4. A casing hanger assembly for use with a casing head having a shoulder therein, comprising in combination:

(a) a casing hanger mandrel having a segmented shoulled therein adapted to land on said shoulder of said casing head, said segmented shoulder providing an annular path between said mandrel and said casing head through which fluid returns can pass when said mandrel is landed on said shoulder of said casing head, and

(b) means associated with said mandrel for effecting a seal between said mandrel and said casing head, said means being so arranged and constructed as to permit fluid returns to pass between said mandrel and said casing head before said seal is efiected.

5. The apparatus of claim 4 including means associated with said segmented shoulder for locking said mandrel against upward movement relative to said casing head when said mandrel is landed in said casing head 6. A casing hanger assembly for use with a casing having a shoulder therein, comprising in combination:

(a) a casing hanger mandrel adapted to land on said shoulder of said casing head,

(b)means defining an annular path between said mandrel and said casing head through which path fluids can pass when said mandrel is landed on said casing head shoulder,

(c) sealing means associated with said mandrel,

((1) means for actuating said sealing means to effect a seal between said mandrel and said casing head, and

(e) said sealing means being so arranged and constructed as to extend said annular path past said sealing means before said sealing means are actuated to effect said seal.

7. The apparatus of claim 6 wherein said actuating means are fluid ope-rated.

8. The apparatus of claim 7 wherein said sealing means are mechanically held in sealing position after said actuating fluid pressure is released.

9. The apparatus of claim 7 wherein said fluid actuating means are pressure balanced to prevent premature sealing of said sealing means by pressure differentials to which the actuating means may be subjected prior to intentional actuation.

10. A casing hanger assembly for use with a casing head having a shoulder therein, comprising incombination:

(a) a casing hanger mandrel adapted to land on shoulder of said casing head,

(b)means defining an annular path between said mandrel and said casing head through which path fluids can pass when said mandrel is landed on said casing head shoulder,

(c) an extrudable packer associated with said mandrel, and t (d) means associated with said mandrel for extruding said packer between said mandrel and said casing head to etfect a seal therebetween,

(e) said packer being so arranged and constructed as to extend said annular path past said packer before said packer is extruded.

11. A casing hanger assembly for use with a casing head having a shoulder therein, comprising in combination:

(a) a casing hanger mandrel adapted to land on said shoulder of said casing head,

(b) means defining an annular patch between said casing hanger mandrel and said casing head through which path fluids can pass when said casing hanger mandrel is landed on said shoulder of said casing head,

(c) sealing means associated with said casing hanger,

mandrel, and

(d) a setting sleeve surrounding said casing hanger mandrel and adapted to be driven downwardly to set said sealing means and thereby eifect a seal between said casing hanger mandrel and said casing head,

(e) said sealing means and setting sleeve being so said arranged and constructed as to extend said annular path past said sealing means before said seal is effected. 12. The apparatus of claim 11 including fluid actuated means for driving said sleeve downwardly.

13. A casing hanger assembly for use with a casing head having a shoulder therein, comprising in combination:

(a) a casing hangermandrel adapted to land on said shoulder of said casing head,

(b)means defining an annular path between said mandrel and said casing head through which path fluids can pass when said mandrel is landed on said casing head shoulder,

(c) an extrudable packer associated with said mandrel, and so arranged and constructed that said path 15. A casing hanger. assembly for use with a casing.

head having a shoulder the-rein, comprising in combination:

(a) a casing hanging mandrel having a shoulder thereon adapted to land on said shoulder of said casing head,

(b) said mandrel shoulder having a longitudinally extending slot thereon through which fluid returns can pass when said mandrel is landed in saidcasing head, and

(c) sealing means associated with said mandrel for effecting a seal between said mandrel and said casing head,

(d) Said mandrel and sealing means being so arranged an constructed as to provide an annular path in fluid communication with said slot, between said casing head and said sealing means for the passage of fluid returns before said seal is effected.

16. A casing hanger assembly for use with a casing head having a shoulder therein comprising in combination:

(a) a casing hanger mandrel. adapted to land on said shoulder of said casing head, (b) means defining an annular path between said mandrel and said casing head through which path fluids can pass when said mandrel is landed on said casing head shoulder,

(c) locking means movably associated with said mandrel for locking said mandrel against upward movement relative to said casing head when said mandrel is landed on said shoulder of said casing head, said locking means being of a configuration to permit fluid returns to pass through the annulus between said mandrel and said head past said locking means,

(d) an extrudable packer positioned around said mandrel,

(e) a drive sleeve threadably surrounding said mandrel above said packer, said drive sleeve having an upper splined portion, (f) said packer being so arranged and constructed as to permit fluid returns to pass between said packer and said casing head before said packer is extruded, and (g) rotatable means adapted to engage said splined portion whereby said drive sleeve may be moved downwardly relative to said mandrel to extrude said packer between said mandrel and said head. 17. A casing hanger assembly for use with a casing head having'a shoulder therein, comprising in combination:

(a) a casing hanger mandrel adapted to land on said shoulder of said casing head, (b) mean defining an annular path :between said emandrel and said casing head through which path fluid can pass when said mandrel is landed on said shoulder of said casing head,

() locking means movably associated with said mandrel for locking said mandrel against upward movement relative to said casing head when said mandrel is landed on said shoulder of said casing head, said locking means being of a configuration to permit fluid returns to pass through the annulus between said mandrel and said head past said locking means,

(d) an extrudable packer positioned around said mandrel,

(e) a setting sleeve disposed around said mandrel within said head, said sleeve having a shoulder means therein,

(f) a first annular ring positioned between said sleeve and said mandrel said ring being adapted to bear against said sleeve shoulder means, and being slida'ble on said mandrel,

g) a second annular ring positioned between said sleeve and said mandrel and being afiixed to said mandrel,

(h) said first and second annular rings being spaced apart and defining a first chamber with said sleeve and said mandrel, and

(i) means for applying fluid pressure to said chamber to thereby move said setting sleeve downward to extrude said packer between said casing head and said mandrel.

18. The apparatus of claim 17 including means for preventing upward movement of said sleeve relative to said mandrel.

19. The apparatus of claim 17 including an equalizing chamber defined between said sleeve and said mandrel by the surface of said first annular ring opposite said first chamber and a third annular ring spaced apart from said first annular ring and means for subjecting said equalizing chamber to the pressure to which said first chamber is subjected except when said packer is being set.

20. The apparatus of claim 19 wherein said pressure applying means include a setting tool releasa'bly connected to said mandrel, and including (a) a sealing seat in said setting tool between said chambers and adapted to receive a setting ball to seal the bore of said setting tool between said chambers, and

(b) means below said sealing seat for subjecting said equalizing chamber to the pressure to which said first chamber is subjected when said packer is not being set.

21. A method for hanging a casing string in a well drilled in a formation, within a casing head having a shoulder therein and wherein a casing hanger mandrel is attached to said string and adapted to land on said shoulder to thereby operatively hang said casing string in said well, said mandrel including packing means for sealing between said mandrel and said casing head the steps comprising:

(a) installing said casing string on said mandrel,

(b) lowering said string and said mandrel into said casing head to such a depth that said mandrel lands on the shoulder of said casing head in final longitudinal position relative to said casing head,

(0) cementing said string into said formation and returning fluids upwardly between said mandrel and said casing head, and

(d) thereafter sealing between said mandrel and said casing head by setting said packing means therebetween prior to retrieving the running and setting tool,

22. A method of hanging a casing string in a well drilled in a formation within a casing head having a shoulder therein and wherein a casing hanger mandrel is attached to said spring and adapted to land on said shoulder to thereby operatively hang said casing string in said well, said mandrel including packing means for sealing between said mandrel and said casing head, the steps comprising:

(a) installing said casing string on said mandrel,

(b) lowering said string and said mandrel into said casing head whereby said mandrel lands on the shoulder of said casing head,

(0) locking said mandrel against upward movement relative to said casing head,

(d) cementing said string in said formation and returning fluids upwardly through the annulus between said mandrel and said casing head, and

(e) thereafter sealing between said mandrel and said casing head by setting said packing means therebetween prior to retrieving the running and setting tool.

23. A casing hanger assembly for use with a casing head having a shoulder therein, comprising in combination:

(a) a casing hanger mandrel having an interrupted shoulder therein adapted to land on said casing head shoulder, said interrupted shoulder providing an annular path between said mandrel and said casing head through which fluid returns can pass when said mandrel is landed on said shoulder of said casing head, and

(b) means associated with said mandrel for effecting a seal between said mandrel and said casing head, said means being so arranged and constructed as to permit fluid returns to pass between said mandrel and said casing head before said seal is effected.

24. A casing hanger assembly for use with a casing head having a shoulder therein, comprising in combination:

(a) a casing hanger mandrel having means thereon for landing said casing hanger mandrel on said casing head shoulder,

(b) means defining an annular path between said casing hanger mandrel and said casing head through which path fluids can pass when said mandrel is landed on said casing head shoulder, and

(c) means associated with said mandrel for effecting a seal between said mandrel and said casing head, said means being so arranged and constructed as to extend said annular path from said landing means past said seal means before said seal is effected.

25. A casing hanger assembly for use with a casing head having a shoulder therein with an upwardly facing surface and a downwardly facing surface, comprising in combination:

(a) a casing hanger mandrel adapted to land in said casing head on the upwardly facing surface of said shoulder,

(b) means associated with said mandrel for locking against said downwardly facing surface of said shoulder to thereby lock said mandrel against upward movement relative to said casing head when said mandrel is landed in said casing head,

(c) means defining an annular path between said mandrel and said casing head through which path fluids can pass when said mandrel is landed in said casing head, and

((1) means associated with said mandrel for effecting a seal between said mandrel and said casing head, said seal means being so arranged and constructed as to extend said annular pat-h past said seal means before said seal is eifected.

26. A casing hanger assembly for use with a casing head having a shoulder therein, comprising in combination:

(a) a casing hanger mandrel adapted to land on said shoulder of said casing head,

(b) means defining an annular path between said mandrel and said casing head through which path fluids can pass when said mandrel is landed on said casing head shoulder,

(c) locking meaens movably associated with said mandrel for locking said mandrel against upward movement relative to said casing head when said mandrel is landed on said shoulder of said casing head, said locking means being of a configuration to permit fluid returns to pass through the annulus between said mandrel and said head .past said locking means,

(d) an extrudable packer postioned around said mandrel,

(e) a setting sleeve disposed around said mandrel within said head, said sleeve having a slip bowl therein, (f) a slip member postioned in said slip bowl around and operatively engaging said mandrel,

(g) a first annular ring positioned between said sleeve and said mandrel, said ring being adapted to abut the upper surface of said slip member,

(h) a second annular ring postioned between said sleeve and said mandrel and being aflixed to said mandrel,

(i) said first and second annular rings being spaced apart and defining a first chamber with said sleeve and said mandrel, and

(j) a setting tool releasably affixed to said mandrel and having a lateral port,

(k) said mandrel having a lateral port therein providing fluid communication between said setting tool port and said chamber.

CHARLES E. OCONNELL, Primary Examiner.

JACOB L. NACKENOFF, Examiner.

(c) means below said sealing seat for subjecting said equalizing chamber to the pressure to which said first chamber is subjected when said packer is not being set.

References Cited by the Examiner UNITED STATES PATENTS 2,104,808 1/ 1938 Neuhaus et a1 285142 3,033,290 5/1962 Brown 166-497 X 3,050,117 8/1962 Haeber et a1 166-21 3,068,027 12/1962 Lewis et al. 166-86 X 3,158,201 11/ 1964 Springer 166-208 X 25 D. H. BROWN, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 ,279, 539 October 18 1966 Cicero C. Brown et al.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1, line 40, for "dose" read does column 3, line 29, for "The shoulder" read The external shoulder column 5, line 69, for "linear" read liner column 6, line 62, for "casting read casing line 69, for "annular" read annulus column 7, line 55, for "patch" read path column 8, line 35, for "an" read and column 10, line 75, for "meaens" read means Signed and sealed this 12th day of September 1967.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

1. A CASING HANGER ASSEMBLY FOR USE WITH A CASING HEAD HAVING A SHOULDER THEREIN, COMPRISING IN COMBINA TION: (A) A CASING HANGER MANDREL ADAPTED TO LAND ON SAID SHOULDER OF SAID CASING HEAD; (B) MEANS DEFINING AN ANNULAR PATH BETWEEN SAID MANDREL AND SAID CASING HEAD, THROUGH WHICH PATH FLUIDS CAN PASS WHEN SAID MANDREL IS LANDED ON SAID CASING HEAD SHOULDER, AND (C) MEANS ASSOCIATED WITH SAID MANDREL FOR EFFECTINH A SEAL BETWEEN SAID MANDREL AND SAID CASING HEAD, 